This invention relates to a horizontal blind opened and closed by turning slats thereof, and more particularly to a blind enabling a light introducing position thereon to be selected in the vertical direction, and, moreover, a boundary between light introducing and shielding portions thereof to be set freely.
In a horizontal blind of the related art, rudder cords are brought down in the vertical direction from left and right portions of a head box fixed to an upper portion of a window frame, and plural pieces of horizontally extending slats are retained in parallel with one another at predetermined intervals by these left and right rudder cords, the plural slats in this condition being opened and closed by turning the same simultaneously by operating the rudder cords.
When it is possible to select a light introducing position on a blind in the vertical direction in order to prevent an image on a picture frame of a computer from becoming hard to be seen due to the light entering an office and the like through a window thereof, or the information shown on such a picture frame from leaking through the window, an ideal environment in which a necessary part only of the inside of the office is lighted with the other thereof shaded can be obtained.
To meet such a requirement, a blind disclosed in Japanese Utility Model Publication No. 3517/1987 is provided with two systems of independently operable rudder cords brought down from a head box, and upper and lower groups of slats fixed to these two systems of rudder cords are operated independently, whereby a light introducing position on the blind can be selected in the vertical direction.
However, since this blind has a structure in which the upper and lower groups of slats are fixed to two systems of rudder cords and operated independently of each other, a boundary between light introducing and shielding portions of the blind cannot be varied as necessary. Namely, an environment in which an image on a picture frame of a computer becomes hard to be seen due to the light entering an office through a window thereof and leaks out through the window differs in various ways depending upon the design of the office and the arrangement of desks, so that the blind in which the boundary between the light introducing and shielding portions are fixed cannot attain the ideal lighting suited to the condition in each office.